Prop selection issues HELP PLEASE
 

OK i am sure this is topic the ppl get tired of talking about. but any help and advice would be nice. My boat is a 1987 four winns 241 liberator with a stk 454 330hp motor and someone put a bravo 1 on it( thank you to whoever did that ). The motor runs strong and no issues there. The prop on my boat by then number is an older mirage( not the plus ) 21 pitch 14 3/4 inch dia. Last year the boat would do about 48mph most day while running 4400ish rpm. Now my drive is the 1.5 ratio bone stk motor, rpm is right one checked it agains two tachs, that gives me about 17 percent of slip. i normaly run my boat with about 50 gals of gas and 3 to 4 ppl on board. i know libs are heavy boats not sure what it is exactly.

The prop was real suzzy looking so i had it polished and balanced at a local but prop shop that has a good rep. now the motors goes to about 4500 but the boat only goes 40mph like 33% of slip.

props i have tried the stk 13 3/4 21p 3 blade stainless that came with the boat. last year it turned more rpms with less speed i have 13 3/4 23p 3 blad al. tried it ove the weekend, blew it out of the water getting on plane, eased onto plane finaly got it up running 4000 rpm at 25 mph and the first 3 foot wave caused it to blow out.

I am not an expert but it seems like i need more blade area on the water not really more pitch.

I was thinking some kind of 4 blade.

Now i know 4 blades tend to loose a few mph over 3s for me that is not the biggest issue. I know this boat should run 50ish and i am fine with that. i need a prop that gets me out of the water fast, we have some shallow spots. I do not care its stainless or al, as long as if its stainless it has a rubber style hub. i can see points both ways on both type. for shallow an al with help protect my bravo 1 but with the stainless the soft bottom and small twigs and that wont chew up my blades. ultimantly a 150 buck prop is alot cheaper that bravo 1.

I boat on lake erie so we do get some good waves. so i cant be right on the edge i need a prop with some grip

any idea or sujection would be great. or any idea to WTF might had gone wrong when the shop polished the prop and it to loose that much mph because i sure thought a good polish job would help that prop grib the water seeing how much left over marine growth was stuck on it.....

with your idea and sujections please tell my why you think this would help. not just list me props, i like to know why things work and dont work.

thanks for the help and info

Did you let the prop shop know that when you dropped it off you were 48mph@4400 and when you got it back you were 40@4500 (lost 8mph)?

Are you trimmed up enough?

You definetly need diameter to carry the heavy boat. I would say the mirage 21 was close. If the shop could have trued it up and got you a mile or 2 an hour that would be 50mph and I would say that is really good for that boat with that power. There was one of those around here would run mid 40's with the 330 but wasen't necessarily dialed in.

I have always heard that liberators like michigan ballistic props.

i am running it just how i did last year. I have tried trimming from the bottom all the way till the prop looses grib on the water. surprising it makes very little differance at all. i can feel the nose come up some, but the rpms might change 200 and the mph does not really get any better. i have not gotten back ahold of the prop shop yet justtring to figure out for sure if it the prop that is the issue or not. I was looking at some 4 blade al just to try for cheap, but they are all almost all 14 dia not sure thats the way to go

have you heard of just the smaller libbys liking these or is it most of them. has anyone out there libby or not used one how did it work for you

call power tech props ( www.ptpropeller.com ) great information ,,, bet they will surprise you , doesnt cost a dime to call and ask

Unless they raised the drive and engine when they swapped to a bravo you should not need a 4 blade prop. Look for a Mirage Plus, Ballistic or other bow lifting 3 blade. And stick with SS as you lose a ton of performance with aluminum.

I do not think they lifted anything. I am 6'4 and when at the beach in water in about belly level if my drive is down there is only 6 or so inches below the prop. so the prop is every bit of 2 or 2.5 plus feet down. not sure if this helps my last 241 libby had the same motor and alpha drive it had the factory 13 3/4 21 pitch prop the boat would not hardly come on plane and once there had a hard time pulling any real rpms maybe 3700.....i put a 14.25 19 pitch 4 blade on it and the boat ran tons better came on plane nice and ran about 52. now this same prop that i could even come on plane with last year when testing the boat would about 4800 but less mph than the mirage 21. so to me that means more slip so i sold the prop. Now to me if i can spin and slip a prop on this boat that my last boat could not hardly turn the prop i used on that boat would more than likely not work either.

I talked to hill marine and he recomened his signature pleasure 5 blade in either 19 or 21 pitch. He said try the 19 first if not enough he would exchange it to the 21 as long as not damaged. Does anyone know anything about these props or use them?

I would say that boat should have a Mirage or Mirage plus in a 21 pitch.. Are you sure the engine is tuned???

Before I did anything I'd try a prop that you knew was right and untouched. Borrow one if you can, should be lots of people in your area that can help. If you are getting those RPM's and speed I don't think it would be a spun hub on the prop, but I suppose stranger things have happened. If the data is right they would have to do some pretty major work to screw it up that bad.

There is a prop shop in Gibraltar (the name escapes me right now) that actually has some loaner props and will let you try them out. I would think a 14.25-14.75x19-20 pitch prop should be about right on that boat if everything is in the stock location with a 1.5 ratio drive. Your rpms will bump a bit, but the holeshot will be way better (tolerable) than with a 21".

I also agree with above, there is no need for anything more than a 3-Blade on the boat, seems like everyone with a Liberator with a single has good luck with the Ballistic for some reason...including me.

yeah that is one thing i am sure i am an auto tech and build alot of custom cars and drag cars.... the motor is tuned up motor issue is one thing that i do know and know i do not have any of. motor purs at nice 750 at iidle, plugs look great, newer wires and cap. timing spot on to factory spec, thunderbolt box giving proper timing, no bogs, no gas smell, starts every week with only 1 half pump, holds a solid 40 psi oil pressure when running and 20 when warm idle. If i was having lack of rpms i would look tune up issue.....i am getting too much rpm and not the speed to match the rpms


It has enough power to turn that mirage 21 to 4700-4800 but i dont gain any mph with the last few hundred rpm so i pull it back the mirage 21 i have now is just slipping really bad. I dont know if the shop that did the polish jib actualy polished the cup off some what or not.... i found a friend of freind that is going to let me try his mirage plus 23 i think it will be to much pitch and be slow out of the hole but if my rpms are down and my mph is right it will let me know that they turely screwed my prop up i figure if i can only turn that prop even to 4000 i should get somewhere near 50mph with a normal slip number i figure it should be slow out the hole.

my main concern is not really the total top speed cause i dont get much time to run the boat there. its my cruising speed last year was 30mph at 3000 to 3200 depending on water. now to get 30 its like 3500-3600 i thought the prop had slip issue last year. my cruising speed showed like 23-25% slip and 17% on top end now its mid 30% all the time :eekdrop:

I guess if with this prop i still get crazy slip numbers i need to look at my coupler alot of work just to take a peak.

I want to say thanks for the help and ides

BBC Liberator sounds like you are using a ballistic prop which one do you have your boat? what kind of numbers do you get with yours?



my holeshot is actulay very nice with this prop now. actualy better than last year.....sure it has to do with the slip. I start out with drive almost 100% down, tabs full down i easy it up to around 2000-2300 rpm at that point the bow is just starting to lift, and from there is give throttle, normaly just enough to get into the 4 bbl, she actualy only takes a few seconds to get up onto plane and the rpms are above 4000 as speed finaly start to equal out i pull back to a nice cruise speed. the raise drive some and tabs to level out I would say planing time from the 2000 mark to when i feel the back rise up is not much more than 3 or 4 seconds with almost no bow rise. While sittling if seats i never loose sight of the water in front of me. Last year the nose would defenatly stand a little more cause i would loose sight of the water in front for a second or two

I can totally understand that, I'd try a 21" Ballistic then, they are tough to beat, and like I said, it seems like Liberators love them, best on my 211, it's the best on my 221 and I boat with two 241's that run them, they just wish they had a 20" one for a better holeshot with a loaded boat.

I run a 21" but have a worked over BBC and see about 66 on GPS @ 5150 with a 1.43 OMC drive. This is on a 221 as noted.

Good luck!

there is a new ballistic 14 3/8 21 pitch on ebay for 275 sound like a normal price on one of these. I should be able to get my hands on the friends mirage plus 14 5/8 23 pitch this weekend. I am figuring on it being too much for my boat but should answer my questions on stuff. I assuming i will be slow out of the hole and low in the rpms but should have a good maybe mph with hopefuly little slip. if so maybe a ballistic is the way to go. just looks like they cut off the tups of the blade which i figured would be were the load is carried. just assumed they worked well on lighter boats not big tanks like mine. but it sounds like even these fat girls like them too

thanks for the help will keep everyone posted on what goes down

tried the mirage plus 23 pitch over the weekend its clearly way to much pitch. Hole shot not too bad, rpms were low at wid open throttle only 3900-4000 speed was up to 44 so that is still almost 25% of slip cruising rpm of near 3000 netted me about 31-32 mph still alot of slip???? So clearly there is an issue with my 21pitch prop any idea why the 23 pitch would have so much. are these boats really bad going through the water........when running on plane it feels like the nose is pretty level to water......not up in attitude. I can only trim my drive up maybe just like 2 seconds on the button before it starts to blow out. My trim gauge does not work so i dont have any real way to know where it is for sure. but when down it lake like 6 seconds before trips the limit switch. felt good that i made some improvement till a 27 scarab with 6 ppl blows me lol

BBCliberator the 241 you boat with if you get a chance see if they are running the omc drives and ford or the chevy and mercruisers....be nice to kow what mph and rpms they are running at and if they are mostly stk motors

to me the mid 20s slip still sounds high.....would a 4 blade help get me some more blade surface on the water to improve these number

They both run 460 fords and omc's and run just over 50mph, I think they run somewhere in the 4500 range but I'm not 100% sure, I'll let you know. I have read in several liberator threads that they like 4-blade props, but have no first hand experience...

Sometime when you don't know where to start going back to stock is the right move, call four winns and find out what the stock prop is.

talked with ron hill of marine he recomended a 14.25 19 pitch 5 blade from his pleasure 5 signature series??? anyone know anything about these props. I know this would give me alot of blade area. but that sounds like alot of blades to turn through the water

Interesting, don't know why you'd need a 5-blade on this type of boat, but also have no experience with them either, so I'm sure not going to say it won't work.

Do you know what the stock prop is? Also I did notice you were worried about the trim, these boat run pretty flat at the speeds we are talking, if you are hitting the trim limiter that's close to where you should be. My 211 liked one touch of the trailer button once I hit the trim limiter, but any more the prop would blow out. That should be about right, don't go much past it.

On speedwake.com I've see a thread about liberators that is about a million pages long, it may be worth checking out for prop advice. The thread is "who has a four winks liberator" or something like that

i will check it out, i am no where near that much trim on my drive. if i trim up till my prop starts to slip, i might be maybe halfway to the trim limit switch. maybe its not much trim. My 86 with a 454 and alpha drive came with 13 3/4 21pitch. now that boat would not hardly even get on plane with that prop. I have to run a 4 blade 17 on it. I tried that same prop on this boat and pops up on plane nice turns about 4700 and gets about 45mph so still alot of slip. My boat now is a 87 and i am sure it came with a alpha but now has a bravo.

I am going to recheck my tach seems like maybe something has gotten off there. checked it last year and it was spot on but i want to double check.

Dumb question, you don't have a shorty lower on the bravo or something do you??? Getting blowout before the trim limit with wouldn't be typical, unless it is set wrong or something, and I'm not sure you CAN set them wrong -- if they are set off the trim sender it's a potentiometer and you can adjust that, but I'm not sure how the limiter ties in...especially with a conversion.. Someone else may know that.

I'd get the trim gauge working if you can, you'd have a better reference than "one one-thousand, two one-thousand" :)

i know the gauge itself works cause i can ground it out the gauge will move from one end to the other i hope to have time to see if its a wiring issue or sender issue this week of next i have a sender on order to tie in and turn to see if the gauge works if it does i will pluck the boat and replace it. as far as the shorty outdrive i dont think it is. When floating at the beach in mid chest high water with my gaue saying about 3.5 feet( i am 6'4" ) when i put the drive all the down there is only like 8-10 inches to the sand. i can slide my foot under and lift a few inches. hard to get an exact measurement when the boat moves up and down. but it sits well below bottom of the boat if someone knows the drive measurement i will measure the total drive height and find out

checked my tach over the weekend.....seems like it is about 200 of above 4000 but pretty close below that. I checked it with my snap-on digital timing light that has a tach option in it. I cleaned my 21 mirage up took 2 hours with clr and steel wool to get all the growth that formed in just a few months. double checked both props the 21 mirage and 23 mirage plus ran both direction up river and down, jumped in changed in the water and reran. the 23 pitch netted me 44-45 mph at 3900-4000 rpm 21-23% slip the 21 pitch netted me 42-43mph at 4200-4300 rpm 23-25% slip both props have similar slip number when cruising around 3000 rpm getting 30-32 mph when i throttle up there rpms just sounds unloaded and free revingish almost the speed does not feel like it gain with rpms i figure with that much slip i cant beleive the rpms are not going higher once the numbers are crunched......makes me wonder if i get the slip down if i will still be able to turn that many rpms. during this rounds of test it was me and wife in boat 500 pounds and 1/4 tank of fuel 25 gal.

With both props i still could not trim very much before i started getting alot of slip. I was unable to get the trim gauge worked on to much going on over the holiday with family

there are a couple of rev 4 used props i can find on cl think i should stick with the 21 pitch or drop to a 19 pitch? doing the match seems like if i can the slip percent down i would have a better cruising speed at lower rpm with the higher pitch even in my test i was able to go faster at less rpms with a higher pitch prop. seems to me it would be better to run 50mph at lets say 4100 than to turn 4500 to get the same speed??

Hope everyone had a good 4th

Hmmm...the prop blowout doesn't make sense to me if you are really trimming that little, but I certainly believe you. Ran across this the other day and seeing your reply reminded me. Sounds like you may be able to get some ideas from it. Keep reading, the prop stuff is in there. It's a 251 Liberator, but I suppose it closer to your boat than mine is. His boat likes the 4-Blade.

http://www.speedwake.com/forums/showthread.php?t=72964

One more thing, how positive are you that you have a 1.5 drive ratio? That would explain a lot. It is possible it's a 1.65 ratio or something???

http://bluewatermarinesvc.com/pdf/me...ear_ratios.pdf

If you are unsure I think you can take the cover off the top of the driveshaft housing and count the teeth on the top gear. If the gear has 30 teeth, it's a 1:65, if it has 32 teeth it's a 1.5 and if it has 29 teeth, it's a 1.36. You only need a 3/8" twelve point socket to remove the 4 bolts. Some oil may leak out though. This may be worthless information if you already know for sure.

i have never counted teeth. the numbers on the sticker can not be seen. i was told it was a 1.5 next time the boat is out of the water i will pull that cover off and count....i would think if i had 1.65 gear i would be able to get more rpms out of it than 3900-4000 with the 23 pitch ans 4200-4300 with the 21 pitch. If i am thinking about about this the correct way the higher the number of the gear ratio the more easier it would be to turn higher engine rpm. and i would get less prop rpm. i guess i could pull my dist cap and put the boat into gear and manual crank the motor at the crank and count the turns of the prop. i should get 1.5 motor revs to 1 of the prop something not to hard to do in the water I am thinking about this the correct way correct? The motor turns faster than the prop just like gear ration in a gear?? engine revs is the first number to output revs as the second??????

The higher the ratio, the less the prop turns, so more rpm's to maintain the same speed. I guess what I am getting at is the 1.65 ratio puts your slip #'s more into the normal range. I can't believe all the props are slipping THAT much. Is the boat extra heavy and dragging in the water? Maybe waterlogged wood? Foam? etc. Is the motor NOT making full power, is it tired? and it's only getting the rpm's since it's got a higher ratio?

You've pretty much solved the prop question you end up in the 20+ range for slip on everything, now the question is why. If you knew the drive ratio 100% that may lead you down a different path. What I do know is that is a 50+mph boat, and something isn't adding up. You could do it in the water, but the different between 1.5 and 1.65 may be hard to see, not sure never tried.

You did have RPM and speed data from earlier though, the very first post says 4400 at 48MPH, that makes sense if your #'s are accurate and would indicate a 1.5 drive. The question is what changed...

By the way which way was your stock tach off, does it read high or low? I mean, are those #'s still valid since you now know the tach is off???

EDIT: Just thinking out loud.... i just don't have anything more useful for you at this point ;)

the boat does not seem water logged. I got good mph last year and it sat in inside storage all winter. My boat does sit in the water all summer but each week i do not get much water out of it in the bildge. If it does not rain some weeks even when i turn it on nothing comes out. What is a good way to check for this. The boat does not sit low in the water. it is down a little ing the back.....not as much as alot of other performance boats. it does lean to the starboard side....did this last year too....but both batteries are on that side....so is the fridge and the water tank.....just figured that was why

The motor seems strong, hold 40psi oil at idle and 60 when running. I actualy think the motor was changed sometime in the boats life. The oil dipstick is on the port rear corner where my other one was on the starboard front. Has over 150 cranking psi on all cylinders, never did a leak done test. But seems smooth and strong so i never looked into it.

Last year i checked the tach the same way and it was spot on this year reads 200 high so 4400 on my tach showed 4200 on the timing light

I will check the ratio this weekend. It should not be that hard to ID one blade put it straight up, put the boat in gear, pull the cap, referance the rotor location. hand crank the motor over till the prop blade get back to where it started and look to see if the rotor went 1.5 times around or 1.65( little more than 5/8) that should be very noticable on the rotor. I know alot of ppl run a 21 pitch prop on these boats and similar and turn 4200-4500 rpm with no issue.......using 1.5 ratio i would figure if i had a 1.65 ratio it would be easier to turn more rpms or a larger pitch prop. my rpms at 4200 with the 21 pitch and 3900 with the 23 seems very correct? but i will check

I agree it should be 50 mph boat i thought the prop had alot of slip last year that why i had the prop polished to get the scuzz off the try to help that hopefuly. The mirage and mirage plus are very similar style of prop so if for some reason my boat does not like that prop make since switching to 23 pitch from 21 would not change the world. I used the 23 just to try to figure out if it was my prop or not. I have also tried a 13 3/4 21 and 23 pitch 3 blade al props both had a hard time handling the rpms and power. they both blew out very easy and had a hard time even geting on plan and up to 30 mph I wish i had a 4 blade prop to try to see my last libby i ran a 14.25 4 blade 19 pitch and it seemed to work well. it came with a 13 3/4 21 pitch 3 blade stainless but would not even get on plane with it...........i tried that prop last year on my new boat and runned more rpms with less speed so i sold it

the boat is still very useable the way it is just not right. i will have some more answers after the weekend. But you have made a very good point about the gear ratio and will check it........not sure how to check to water logged

I do thank you for your time and thoughts on this issue you have brought up some good points and things to think about. I guess if i have a 1.65 ratio i need to find out why i cant turn more rpms....

I mean, everything you say about the engine makes me think it's fine too, have you checked the timing at say 3000rpm or up, to make sure it's getting full advance?

The best way to check for water logging is simply to weigh the boat...another not so trivial task....a whole bunch of extra weight would give the results you are describing though... Let's hope that's NOT it, because there isn't a real good solution to that one...at least not easy. If you don't have a lot of water in the bilge are you sure the front drain are draining to the back??? There is a hole in the bulkhead in front of the motor that allows for the front of the boat to drain to the bilge, can you stick your finger in it to see if it's clogged? Or a screwdriver or something?? Is a ton of rot around this drain??? If there is a lot of rot around this drain, that would be an indication there may be a larger problem. Though some softness immediately around this hole would be normal.

What is the bottom condition??? Since you keep it in the water???

You could always pull a valve cover to make sure you are getting full lift??? Now I'm starting to talk crazy....

Without actually being there I am about out of ideas.

the boat does not have tons of extra weight. i normaly run between 25-75 gal gas depending on where we are going but most of the time 25-50 gal. i have 2 13 pound anchors, about 250 feet of rope, 8 lifejackets, 2 al handled plastic folding paddels, 6-8 fishing poles, i normaly do not have water in tank, the potti does have 2 gal water almost in the nose. course the boat has the frdge, nothing in it most of the time

I do not know what these boats should tip the scales at. the four winns site says it 3105 but i know that cant be right...... I know a 454 is close to 600 pounds the manifolds and risers have to 75 a side so thats 150 750 the outdrive is close to 125ish 875 not sure what the housing and gimbal ring weigh maybe 100 so call that 1000 pounds on top of the 3100 four wins says 4100 350 for 50 gal gas i know my wife and i( normaly the only two ppl in the boat ) 550 neither of us are small. so say 5000 lbs running is a fair guess

Does anyone know what a 241 liberator with 454 and bravo should scale in at i do know the bravo is a little heavier than the alpha

last year i had 8 adult on boat and minus getting on plane the boat did not reall slow down any.....


I thought about something else too last year i was using a differant gps than this year wonder if maybe it read fast. My speedo on the boat did not work last year and this year it does seems to be about 2 slower than my gps....i did check it this year on both my gps and my iphone

I will check the drain hole too.......honestly never felt around down there.....would not be hard to run a something up through there just to make sure.......nothing ever seems wet but never know.... I will check all this out this weekend when i get up there.....all good points to check

I think i have the specs for the timing somewhere 8 for base timing and i think the module should give me 22 more or so by 3200 i think 30 total sounds right.

the bottom is clean got a fresh coat a paint this year with bioboost from sea hawk. i do keep the growth off the sides.....the water at the back of the boat goes about 3 to 4 inches of the paint......i had it painted up the factory tristrip did not want to make it look silly on the trailer by painting up that far. i can feel a little slick slime on the bottom that feels very smooth......but nothing big and hairy causing lots of drag

I could pull the covers.......but that means dropping those big heavy manifold and risers........if i was not gettting up the rpms i would think that way. i can get the rpms just not the mph besides if i pulled them off i would be very tempted to add 1.8 roller rockers and that starts a hole other issue i have........always wanting more hp in everything i have.....lol I have 3800 v6 making 400 hp as a daily driver and about 750hp 455 buick racecar......

I dont drive 50+ everywhere i can if it would just want things to be right just want to able to do it if and when i wanted and water was right and safe.....most of my boating is done at 30-35 mph just dont want to have to run extra rpms and gas to get there....

thanks for the help and info it always does good to get another brain or too involved might just uncover the snake sitting right in front of me.

Here is the 88' spec sheet: http://www.fourwinns.com/past_produc...20(p48-49).pdf

The 3100 is boat only, page 2 has total dry weight.

Check back in with what you find, you've got me curious...

Remember the rotor only turns half engine speed so 1 turn of the prop would be 3/4 turn of the rotor for a 1.5 to 1 drive. It would turn .825, or more than 3/4 turn for 1.65:1 drive. Kind of confusing.

Since that boat came with a OMC it probably came with a Raker prop. I have some friends with early 90s 221 Libs and they came with 20" Rakers. One has a stock 454/330hp and runs low/mid 50s with a 20 Raker. I think his drive is a 1.43 so that puts him at about 10 slip.

The could see high slip numbers on the standard Mirage 21 but the high slip numbers on the Mirage+ 23 are baffling.

You leave the boat in the water ? Pull it out an clean the bottom.

The boat this thread is about has a Bravo on it, but you are correct, mine cam with a 14.5x20 Raker on the OMC. Viper props were the other big stock OMC prop.

That's where I am at with the slip, something isn't adding up, we'll know more once he verifies exactly what he has.

I saw it had a Bravo. I was just stating what they came with since it was asked.

Either he is trimming up much higher than he thinks or the engine and drive were raised when they swapped to a Bravo. The X dimension on Libs are VERY deep and there is no way he should be blowing out props with little trim.

I would verify the X and trim angle.

This one started life with an alpha. But I get your point.

And I totally agree with that, that's what has me confused too, blowout shouldn't be an issue for sure.

Ahhh I didn't catch the Alpha part.

I agree you should be able to trim a Lib to the moon before it blows out. On my buddies Libs I'd guess the propshaft is 7-8" below the boat.

I actually asked him if he for some reason has a shorty lower on it, but I don't know or have the dimensions to look for.

Yeah on both my libs you could trim them forever before they would blow out.

It's always fun to try to unravel a mess from the past when you have no history....

Yes this boat did come with the alpha drive and mow has the bravo. I dont think they raise or motor. my prop shaft is at least 8 inches below the boat........i will try to take a measurement

yes the boat sits in the water......no its not all covered in stuff. I have the bottom painted with seahawk paint and bioside.......after 6 months last year sitting in the water there was very little build up just a thin slim coating that you could use you hand to rub it off. I recoated this year with the same stuff i keep the bottom wiped with a rag every week at the beacj and the side above the paint scrubbed with a brush to keep it from building up. no there is not a build up or marine growth....i hate to leave it sit but bottom paint does a good job......i cant drive a truck up to lake erie every weekend....and the dock only cost me 300 a year cheaper than driving the truck every weekend.

With the trim gauge not working the only thing i can think to do is measure from the water to the prop shaft........trim it till it looses grip shut it down and measure again to see how much........but its truely not even halfway to the limit switch.....the limit switch stops it about 1/3 of the through the travel and trailer button gets the rest of it. And just before someone asked no i do not have the buttons mixed up.

If someone know the length of a bravo 1 reg drive compaired to shorty i will measure to find out. What i do know is at my dock the water depth by my gauge is 3.5 feet below the bottom of the boat.......it has a shoot through the hull transducer. i am 6'4" and the 3.5 feet of read is is actualy about halfway up my chest i would say about 4 feet deep in honesty cause the soft mud bottom i sink in about 6 inches or so into the soft mud. at this 3.5 to 4 feet of water if my drive is all the way down there is 8 inches so before before the lowest part of the skeg not sure if that helps.......but to me that does not seem like the drive has been raised too much

IF someone has a 241 liberator on a trailer that has a bravo drive if they could measure from the prop shaft to something referance point on the boat.....the drain plug , top of the back of the boat...... remember my boat is in the water.....so points below water will be hard to hold against and measure......

And i dont think comment on the engine rpm ratio is right.. there is 2 crank turns to 1 cam so the piston in each cylinder goes up and down twice to make 1 revolution. Rpms on a tach are a measure of cam shaft rpm. but i know the crank drives the coupler and input shaft.....and its direct to the crank......so maybe i am thinking of it wrong.... so maybe the prop would turn faster now MR Maine has my brain turning....lol ok thinking out loud hear. the crank drive the input shaft the ratio is for the input to output......1.5 input to 1 output input is equal to crank revs not cam revs... 1 crank equals half cam. so yeah Mr Maine is right .75 dist rotor to 1 prop its been a long week already my brain is toasted....i RETRACT WHAT I SAID Mr Maine is right.... anything more 3/4 dist rotor would be a higher number ratio 1.65 anything less would be a lower number ratio 1.3x



thanks again to all who are coming up with ideas to help. i would rather cross the t's and dot the i's than spend money wastefuly

That is a good idea just so you know.

The Mirage + 23 didn't have open vent plugs did it?

no it does not even have the spots for the vent plugs part number 48-13704 23p should not matter either way....boat has rear exit through no exhaust goes through the outdrive and prop the mirage 21 does not have them either did any or the pirage or plus have them???

Got ya. Even if you have thru-hull exhaust it can give you some serious ventilation and even blow out.